YACT yet another compression test thread. MS290, 105psi? Newish Poulan, 105psi?

[ham]

Okay either way this is with choke off and WOT

Replacing the handle is a serious amount of work. I really want to verify compression. If this compression tester isn't the right one, then what do you guys use?

 

[cuinrearview]

I don't really too much anymore

 

[Bob Hedgecutter]

Meh, that little difference could be a lot of things.

Like equating in the non scientific factor of the monkey on the rope?

 

[Bob Hedgecutter]

Okay either way this is with choke off and WOT

Replacing the handle is a serious amount of work. I really want to verify compression. If this compression tester isn't the right one, then what do you guys use?

Compression tests on small capacity 2 stroke engines can be "interesting" at the very least with a non specific gauge, or rather without a gauge specifically set up to meter small amounts of volume accurately and repetitively.
You say the saw runs well- leave it at that, correct carb settings and fuel mixture, it will probably continue to run for years.
Buy yourself a new rear handle/tank assembly, swap the parts over and enjoy your saw.

Striving for an "ideal" compression reading off a less than ideal gauge is a bit like demanding a saw must be tuned to some factory RPM level at WOT for it to be tuned correctly.

 

[RED-85-Z51]

Okay either way this is with choke off and WOT

Replacing the handle is a serious amount of work. I really want to verify compression. If this compression tester isn't the right one, then what do you guys use?

I just got a Strandix 1023 that is pretty much identical to the 125 dollar unit Echo used to sell to dealers for 1/3 the money.

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[SteveSr]

If so, why does it read accurately when tested with my air compressor (the compressor has two quality, matching gauges dead at 125psi with a good 25’ hose). Also, what can I do to fix it? If there’s some underlying issue with the 290 I don’t want to spent money and a lot of time swapping the rear handle

The adapter on the end of the hose is effectively adding volume to the cylinder that you are trying to measure lowering the reading.

 

[SteveSr]

Okay either way this is with choke off and WOT

Replacing the handle is a serious amount of work. I really want to verify compression. If this compression tester isn't the right one, then what do you guys use?

Pull the muffler and look at the piston... If it looks good (no scoring) then run it!

 

[ham]

I just got a Strandix 1023 that is pretty much identical to the 125 dollar unit Echo used to sell to dealers for 1/3 the money.

Sent from my LM-G820 using Tapatalk

Thx, I just ordered one from ebay

 

[ham]

Pull the muffler and look at the piston... If it looks good (no scoring) then run it!

Yep I posted pics in the 2nd post to the thread. Piston is beautiful

 

[cuinrearview]

Looks too short right,this would reduce the compression. You need a different setup the threads should be the exact same length as the plug threads.

If the valve is at the end of the hose that adapter adds a bunch of volume.

 

[ham]

I just got a Strandix 1023 that is pretty much identical to the 125 dollar unit Echo used to sell to dealers for 1/3 the money.

Sent from my LM-G820 using Tapatalk

Update - the stradix from ebay gave me 152psi. So it was that tester with the long hose without the valve on the threaded end of the hose causing my bad readings. Thx all

 

[RED-85-Z51]

Update - the stradix from ebay gave me 152psi. So it was that tester with the long hose without the valve on the threaded end of the hose causing my bad readings. Thx all

Thats a solid number. Youll like the strandix, very easy to use.

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